An actuator includes: a movable body including a single-pole magnetized single pole magnet; and a plurality of electromagnets each having a magnetic core portion and a coil portion for exciting the core portion. The actuator has: a fixed body on which three or more magnetic poles of the electromagnets are disposed at positions orthogonal to the magnetization direction of the single-pole magnet; and an elastic body bridged between the movable body and the fixed body and elastically deforming when current is supplied to the coil portion, thereby supporting the movable body so as to be movable in the magnetization direction of the single-pole magnet and the two-degree-of-freedom direction. The elastic body is attached to the movable body so that the movable center of the movable body matches the substantial center of the generated magnetic torque of the movable body.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An actuator comprising: a movable member including a unipolar magnet magnetized in a unipolar fashion; a fixing member including a plurality of electromagnets each including a core as a magnetic substance and a coil for exciting the core, wherein three or more magnetic poles of the electromagnets are disposed at respective positions orthogonal to a magnetization direction of the unipolar magnet; and an elastic body provided between the movable member and the fixing member, and configured to be elastically deformed when a current is supplied to the coil so as to movably support the movable member in a magnetization direction of the unipolar magnet and in two-degree-of-freedom directions, wherein: the elastic body is attached to the movable member such that a movement center of the movable member coincides with an approximate center of a generated magnetic torque of the movable member, the elastic body comprising: a ring part externally fitted on a periphery of the movable member; and a plurality of elastic arm parts extending outwardly from the ring part and connected with the fixing member, and each of the plurality of elastic arm parts is disposed between adjacent electromagnets of the plurality of electromagnets on a horizontal plane that passes through the approximate center of the generated magnetic torque.
2. The actuator according to claim 1 , wherein the electromagnets move the unipolar magnet in the two-degree-of-freedom directions with sequential excitation of the magnetic poles such that the movable member performs precession.
3. The actuator according to claim 1 , wherein the movable member includes magnetic substances provided on respective magnetic pole surfaces of the unipolar magnet.
4. The actuator according to claim 1 , wherein the elastic body is a leaf spring.
5. The actuator according to claim 1 , wherein the unipolar magnet is movably disposed at a position where the unipolar magnet is surrounded by the electromagnets.
6. The actuator according to claim 1 , wherein the unipolar magnet is a neodymium magnet.
7. The actuator according to claim 1 , wherein the unipolar magnet is a ferrite magnet.
8. The actuator according to claim 1 , wherein the elastic body is composed of a non-magnetic material.
9. The actuator according to claim 1 , wherein the movable member is supported by a plurality of the elastic bodies.
10. The actuator according to claim 1 , wherein an input frequency of power supplied to the electromagnets is substantially equal to a rotation resonance frequency of the movable member.
11. An air pump comprising the actuator according to claim 1 .
12. An aesthetic apparatus comprising the actuator according to claim 1 .
13. A laser scanning apparatus comprising the actuator according to claim 1 .
14. The actuator according to claim 1 , wherein: the fixing member includes N (N is an even number) electromagnets disposed around the unipolar magnet at even intervals; and the N electromagnets allow the movable member to reciprocate in a direction tilted with respect to the movement center when magnetic poles of N/2 electromagnets of a first group adjacent to each other are set to one magnetic pole with excitation, and magnetic poles of remaining N/2 electromagnets of a second group which are opposite to the N/2 electromagnets of the first group are set to the other magnetic pole opposite to that of the electromagnets of the first group with excitation.
15. The actuator according to claim 1 , wherein each of the plurality of elastic arm parts comprises a zigzag part extending in a zigzag manner between the adjacent electromagnets on the horizontal plane.
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April 23, 2015
April 7, 2020
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